Purpose: To determine the prevalence of abnormalities in the nutritional status, and their correlation with pulmonary function test results, in a population of outpatients with stable chronic obstructive pulmonary disease (COPD).
Patients and methods: During 1 year of study, body weight, height, triceps skinfold, arm muscle circumference, and pulmonary function parameters were assessed in 126 patients. On the basis of body mass index (BMI = weight/height2) of less than 20, 20 to 27, and greater than 27, the patients were divided into underweight (n = 29, 23%), normal weight (n = 67, 53.2%), and overweight (n = 30, 23.8%), respectively.
Results: Diffusing capacity for carbon monoxide (DLCO), both as absolute and percent predicted, differed significantly among the three groups, being lowest in the underweight and highest in the overweight patients. A significant and positive correlation was present between BMI as the independent variable and DLCO, forced expiratory volume in 1 second, and its ratio to forced vital capacity. A significant and negative correlation existed between BMI and residual volume and its ratio to total lung capacity.
Conclusion: A substantial number of stable COPD patients (46.8%) have nutritional abnormalities. BMI is a simple and accurate indicator of nutritional status in these patients. BMI correlates significantly with some tests of pulmonary function.